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Terms modified by GM Selected AbstractsThe antecedents of non-affective psychosis in a birth-cohort, with a focus on measures related to cognitive ability, attentional dysfunction and speech problemsACTA PSYCHIATRICA SCANDINAVICA, Issue 4 2010J. Welham Welham J, Scott J, Williams GM, Najman JM, Bor W, O'Callaghan M, McGrath J. The antecedents of non-affective psychosis in a birth-cohort, with a focus on measures related to cognitive ability, attentional dysfunction, and speech problems. Objective:, Adults with non-affective psychosis show subtle deviations in a range of developmental trajectories as children and adolescents. Method:, Based on a birth-cohort (n = 3801), we examined the Peabody Picture Vocabulary Test (PPTV) at age 5, and Raven's Standard Progressive Matrices (RSPM) and Wide Range Achievement Test reading scale (WRAT-R) at age 14. Items related to speech problems and attentional dysfunction were available from maternal- or self-report. At age 21, we identified 60 cohort members who were screen-positive for non-affective psychosis (SP-NAP). Results:, Impaired performance on the PPVT and RSPM (but not WRAT-R) predicted SP-NAP for males only. Male cohort members in the highest quartile for attentional dysfunction at ages 5 and 14 were about 5,8 times more likely to develop SP-NAP. SP-NAP in males was significantly associated with speech problems at age 14. Conclusion:, Males who develop non-affective psychoses have subtle impairments in cognitive capacity prior to the development of their psychotic disorder. [source] Right Ventricular Function Assessment: Comparison of Geometric and Visual Method to Short-Axis Slice Summation MethodECHOCARDIOGRAPHY, Issue 10 2007Daniel Drake M.D. Background: Short-axis summation (SAS) method applied for right ventricular (RV) volumes and right ventricular ejection fraction (RVEF) measurement with cardiac MRI is time consuming and cumbersome to use. A simplified RVEF measurement is desirable. We compare two such methods, a simplified ellipsoid geometric method (GM) and visual estimate, to the SAS method to determine their accuracy and reproducibility. Methods: Forty patients undergoing cine cardiac MRI scan were enrolled. The images acquired were analyzed by the SAS method, the GM (area and length measurement from two orthogonal planes) and visual estimate. RVEF was calculated using all three methods and RV volumes using the SAS and GM. Bland,Altman analysis was applied to test the agreement between the various measurements. Results: Mean RVEF was 49 ± 12% measured by SAS method, 54 ± 12% by the GM, and 49 ± 11% by visual estimate. There were similar bias and limits of agreement between the visual estimate and the GM compared to SAS. The interobserver variability showed a bias close to zero with limits of agreement within ±10% absolute increments of RVEF in 35 of the patients. The RV end-diastolic volume by GM showed wider limits of agreement. The RV end-systolic volume by GM was underestimated by around 10 ml compared to SAS. Conclusion: Both the visual estimate and the GM had similar bias and limits of agreement when compared to SAS. Though the end-systolic measurement is somewhat underestimated, the geometric method may be useful for serial volume measurements. [source] Gender and the Council of Emergency Medicine Residency Directors Standardized Letter of RecommendationACADEMIC EMERGENCY MEDICINE, Issue 9 2004Daniel V. Girzadas Jr. MD Abstract Objectives: Until 2002, the Council of Emergency Medicine Residency Directors standardized letter of recommendation (SLOR) prompted authors to predict how an applicant would rank on their match list. A ranking of guaranteed match (GM) was identified as the least common superlative response on the SLOR. That knowledge allowed precise identification of the best SLORs. The authors correlated GM with every possible author/applicant gender combination. Methods:This was a retrospective, observational study of 835 SLORs submitted in the 1998,1999 and 1999,2000 application cycles to one emergency medicine residency program. A standardized data collection instrument was used. Author/applicant gender combinations (M/M, M/F, F/F, F/M, M/M + F/F, and M/F + F/M) were analyzed with respect to GM by chi-square test, odds ratios with 95% confidence intervals, and logistic regression. Results: There was a statistically significant association between a female-authored/female-applicant SLOR and GM, with a female applicant two times more likely to get a GM from a female author than any other author/applicant gender combination (odds ratio, 2.0; 95% confidence interval = 1.1 to 3.8; p = 0.023). No other combination was significantly associated with GM. Conclusions: Female applicants to the authors' emergency residency program had a two times better chance of receiving a GM recommendation on a SLOR written by a female faculty member compared with any other possible gender combination of applicants and letter authors. Although the choice of GM has now been eliminated from the SLOR, the role of gender in relation to the SLOR merits further study. [source] A microfluidic device for characterizing the invasion of cancer cells in 3-D matrixELECTROPHORESIS, Issue 24 2009Tingjiao Liu Abstract A microfluidic device was developed for the study of directed invasion of cancer cells in 3-D matrix with concentration gradient. This device consists of two parallel perfusion channels connected by two cell culture chambers. To mimic extracellular matrix (ECM), gelled basement membrane extract (BME) was used to support 3-D distribution of breast cancer cells (MCF7) in cell culture chambers. A stable linear concentration gradient of epidermal growth factor (EGF) was generated across the chambers by continuous perfusion. Using the device, we investigated MCF7 cell invasion induced by different concentrations of EGF in 3-D matrix. It was found that cancer cells responded to EGF stimulation with forming cellular protrusions and migrating towards high EGF concentration. We further investigated the anti-invasion effect of GM 6001, a matrix metalloproteinase inhibitor. We identified that matrix metalloproteinase inhibition repressed both cellular protrusion formation and cell migration in 3-D matrix. These findings suggest that EGF is able to induce MCF7 cell invasion in 3-D extracellular matrix and this effect is dependent on proteolytic activity. This device is relatively simple to construct and operate. It should be a useful platform for elucidating the mechanism of cancer invasion and screening anti-invasion drugs for cancer therapy. [source] Interpreting sustainable development and societal utility in Norwegian GMO assessmentsENVIRONMENTAL POLICY AND GOVERNANCE, Issue 4 2008G. Kristin Rosendal Abstract This article examines the process of assessing applications for genetically modified (GM) crops or plants for import or commercial planting in Norway. GMO legislation in Norway is closely linked to the EU through the Agreement on the European Economic Area (EEA), to which Norway is a party. A central difference with the EU processes emanates from specific clauses in the Norwegian Gene Technology Act on ,sustainable development' and ,societal utility', which provide a potentially wider leverage for Norwegian authorities to turn down the applications. Research material indicates evidence of an increasingly restrictive practice in the Norwegian evaluations, raising the question of how this can be explained in the face of increasing global acceptance of GMOs. A related question is to what extent and how this result is affected by the trends in the EU. An increasingly restrictive practice may be explained by changes in the access structure to the evaluating body, or it may be due to learning and a growing acceptance of the precautionary principle in this sector. Third, a higher number of rejections may largely be associated with the interest structure pertaining to GMOs in Norway. Final decisions are pending and there are uncertainties concerning how Norwegian authorities will apply the specific criteria of the Gene Technology Act. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [source] The role of political myth in the international conflict over genetically modified foods and cropsENVIRONMENTAL POLICY AND GOVERNANCE, Issue 6 2007Sarah Lieberman Abstract Although the controversy over genetically modified (GM) foods and crops has generated some well known myths, such as ,frankenfoods', there has been little analysis of the political role played by these myths. Yet the significance of myth in the GM debate is considerable: indeed, by reflecting and reinforcing the political stances of the major protagonists, myths have themselves become important components in the conflict. With the aid of theoretical tools derived from Laclau, we examine the notion of political myth, and find that it has three levels: factual error, social meaning and political hegemony. We apply this theory to the GM controversy, distinguishing between substantive GM myths, such as frankenfoods, and procedural GM myths, such as the EU moratorium on GM products. We conclude that if such political myths become powerful enough, they could transform themselves into dominant hegemons , i.e. what Laclau calls social imaginaries , and begin to dictate GM policies across the globe. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment. [source] Voxel-based morphometry of sporadic epileptic patients with mesiotemporal sclerosisEPILEPSIA, Issue 4 2010Angelo Labate Summary Purpose:, In refractory temporal lobe epilepsy (rTLE), gray matter (GM) abnormalities are not confined to the hippocampus but also are found in extrahippocampal structures. Very recently we observed in mild TLE (mTLE) with or without mesiotemporal sclerosis (MTS), GM reductions in regions outside the presumed epileptogenic focus. To date, there are no studies that directly investigate whether whole-brain GM volume differs between rTLE and mTLE. Herein, we used optimized voxel-based morphometry (VBM) to identify GM abnormalities beyond the hippocampus in both rTLE and mTLE with evidence of MTS. Methods:, Brain magnetic resonance imaging (MRI) and optimized VBM were performed in 19 unrelated patients with mTLE, 19 patients with rTLE, and 37 healthy controls. MRI diagnosis of MTS was based on the atrophy of the hippocampal formation and/or mesiotemporal hyperintensity on fluid-attenuated inversion recovery (FLAIR) or T2 images, or both. Results:, No patients (rTLE and mTLE) had generalized tonic,clonic or complex partial seizures for at least 3 weeks before scanning. Both mTLE and rTLE patients showed GM volume reduction of the bilateral thalamus, left hippocampus, and sensorimotor cortex compared with controls. No significant GM difference was found between rTLE and mTLE groups. Discussion:, In both rTLE and mTLE, VBM shows GM reductions not confined to the hippocampus involving mainly the thalamus bilaterally. This finding together with the lack of significant GM differences between the two TLE groups supports the hypothesis that mTLE and rTLE might lie along a biologic continuum, suggesting a pathophysiologic role of the thalamus in partial epilepsy. [source] Forecasting the Adoption of Genetically Modified Oilseed Rape Prognosen hinsichtlich der Einführung von gentechnisch verändertem Raps Prévisions sur l'adoption de colza transgéniqueEUROCHOICES, Issue 2 2009Gunnar Breustedt Summary Forecasting the Adoption of Genetically Modified Oilseed Rape We explore farmers' willingness to adopt genetically modified oilseed rape prior to its commercial release and estimate the ,demand' for the new technology. The analysis is based upon experiments with arable farmers in Germany who were asked to choose among conventional and GM rapeseed varieties with different characteristics. Our analysis has shown that ex ante GM adoption decisions are driven by profit expectations and personal as well as farm characteristics. Monetary and technological determinants such as the gross margin advantage of GM oilseed rape varieties, expected liability from cross pollination and restricted flexibility in returning to conventional oilseed rape growing affect the willingness to adopt GM rape in the expected directions. The results further indicate that neighbourhood effects and public attitudes matter a lot, such that individual farmers may not feel entirely free in their technology choice. Our demand simulations suggest that monopolistic seed prices would be set at between ,50 and ,100 per hectare, leaving farmers with a small share of the GM rent. This raises the question as to whether the farmers surveyed would actually benefit from the approval of GM rape varieties if the technology were to be provided by a single firm. Nous explorons le consentement des agriculteurs à utiliser du colza transgénique avant sa mise en marché et estimons la demande de cette nouvelle technologie. L'analyse se fonde sur des expériences menées auprès de cultivateurs allemands à qui l'on a demandé de choisir entre des variétés de colza conventionnelles et transgéniques aux caractéristiques différentes. Notre analyse a montré que les décisions a priori concernant l'adoption de variétés transgéniques sont fonction des profits attendus et des caractéristiques de l'agriculteur et de l'exploitation. Les facteurs financiers et technologiques comme les avantages des variétés de colza transgénique en termes de marge brute, ainsi que les risques possibles de fertilisation croisée et les contraintes relatives au retour vers des cultures de colza conventionnelles ont les effets attendus sur le consentement à adopter des variétés transgéniques. Les résultats montrent également que les effets de voisinage et l'attitude du public comptent beaucoup, de sorte que les agriculteurs individuels pourraient ne pas se sentir complètement libres de choisir leur technologie. Nos simulations sur la demande semblent indiquer que les prix des semences en situation de monopole seraient fixés entre 50 et 100 , par hectare, ce qui laisserait aux agriculteurs une faible part de la rente transgénique. Cela soulève la question de savoir si les agriculteurs de l'enquête tireraient vraiment avantage de l'approbation de variétés de colza transgéniques si la technologie n'était fournie que par une seule compagnie. Wir untersuchen die Bereitschaft von Landwirten, gentechnisch veränderten Raps einzuführen, bevor dieser auf den Markt gebracht wird, und schätzen die ,Nachfrage' nach dieser neuen Technologie ein. Unsere Analyse stützt sich auf Versuche mit Ackerbauern in Deutschland, bei denen sich die Landwirte zwischen herkömmlichen und gentechnisch veränderten Rapssorten mit verschiedenen Eigenschaften entscheiden mussten. Unsere Analyse zeigt, dass ex ante die Entscheidungen über die Einführung von gentechnisch verändertem Raps aufgrund von Gewinnerwartungen sowie von persönlichen und betrieblichen Charakteristika getroffen werden. Monetäre und technologische Bestimmungsgrößen wie z.B. der Vorsprung des gentechnisch veränderten Raps beim Deckungsbeitrag, die erwartete Haftbarkeit bei Fremdbestäubung sowie die nur eingeschränkte Flexibilität, zum herkömmlichen Rapsanbau zurückkehren zu können, beeinflussen erwartungsgemäß die Bereitschaft, gentechnisch veränderten Raps anzubauen. Desweiteren zeigen die Ergebnisse, dass Nachbarschaftseffekte und öffentliche Meinungen eine große Rolle spielen, so dass sich einige Landwirte womöglich bei der Wahl der Technologie in ihrer Entscheidungsfreiheit eingeschränkt fühlen. Unsere Nachfragesimulationen deuten darauf hin, dass sich monopolistische Saatgutpreise zwischen EUR 50 und EUR 100 pro Hektar bewegen würden, so dass den Landwirten ein kleiner Teil der ökonomischen Rente der GV-Technologie verbliebe. Dies wirft die Frage auf, ob die betrachteten Landwirte überhaupt von der Zulassung der gentechnisch veränderten Rapssorten profitieren würden, wenn die Technologie nur von einem einzigen Unternehmen angeboten würde. [source] GMO Food Labelling in the EU: Tracing ,the Seeds of Dispute'EUROCHOICES, Issue 1 2003Maria L. Loureiro Summary GMO Food Labelling in the EU: Tracinq ,the Seeds of Dispute' Genetically modified (GM) food labelling has become a critical issue in the international trade arena. Policymakers and consumers in the European Union (EU) seem to agree on the need to control the use of biotechnology in the food industry. As a consequence, recently the EU Commission approved a measure that establishes strict rules on genetically modified organisms (GMOs), but which lifts the moratorium on GMO production and marketing. This new Directive deals with mandatory labelling of GM foods and their traceability along the food chain. In spite of the substantial effort made to reconcile the different opinions in the escalating debate about biotechnology, the new GMO regulation seems to be unsatisfactory for too many interest groups. A system of total traceability from ,farm to fork' and mandatory labelling for genetically modified products may be considered too complex and too expensive to implement, particularly by those countries or industries that have produced GMO foods for many years. Yet, giving European consumers the freedom to choose GMOs may be the only option that there is until Europeans restore their confidence in the food system and food regulators. A market or consumer-driven solution may eventually terminate the GMO dispute between the two transatlantic trading blocks. , Assurance , Revenud a ns , Agriculture Européenne ,étiquetage des aliments contenant des organismes génétiquement modifyés (OGM) est devenu une question cruciale sur la scène du commerce international. Tant les décideurs politiques que les citoyens de , Union européenne semblent s'accorder sur la nécessité de soumettre à contrôle , utilisation des biotechnologies dans , industrie alimentaire. En conséquence, la Commission européenne a récemment approuvé une mesure qui établit des règies strictes sur les OGM, mais qui lève le moratoire sur leur production et leur commercialisation. Cette nouvelle directive concerne ,étiquetage obligatoire des aliments contenant des OGM et la façon ? en assurer le suivi dans les filières alimentaires. Ce nouveau règlement OGM, en dépit des efforts réels effectués pour réconcilier les différents points de vue dans la montée du débat sur les biotechnologies, semble inconciliable avec trop de groupes ? intérêts pour être satisfaisant. Un système assurant une traçabilité totale, ,du champ à la fourchette' et un étiquetage obligatoire pour tout produit contenant des OGM, paraît bien trop complexe et coûteux à mettre en ,uvre, en particulier pour les pays ou les industries qui produisent des aliments génétiquement modifyés depuis des années. Et pourtant, il se pourrait bien que la seule façpn de restaurer la confiance perdue des Européens dans le système alimentaire et ses institutions soit justement de leur donner le droit de choisir. La fin de la querelle des OGM entre les blocs commerciaux des deux rives de , Atlantique peut venir de solutions apportées par le marché et issues des consommateurs. Einkommenversicherung in der Europäischen Landwirtschaft Die Kennzeichnung von genetisch veränderten Lebensmitteln ist zu einer der bedeutendsten Streitfragen auf dem Gebiet des internationalen Handels geworden. Politische Entscheidungsträger und Verbraucher in der Europäischen Union scheinen dahingehend überein zu stimmen, dass der Einsatz von Biotechnologie in der Nahrungsmittel-industrie kontrolliert werden sollte. Als Reaktion darauf hat die EU-Kommission kürzlich einer Maßnahme zugestimmt, welche ein strenges Regelwerk für genetisch veränderte Organismen (GVO) festschreibt, mit der aber gleichzeitig das Moratorium für die Produktion und Vermarktung von GVO aufgehoben wird. Die neue Richtlinie beschäftigt sich mit der Pflichtkennzeichnung von genetisch veränderten Nahrungsmitteln und mit ihrer Rückverfolgbarkeit entlang der Nahrungsmittelkette. Trotz der erheblichen Anstrengungen, die verschiedenen Standpunkte in der eskalierenden Debatte um Biotechnologie zu berücksichtigen, scheint die neue GVO Richtlinie in den Augen (zu) vieler Interessengruppen unbefriedigend zu sein. Ein System der vollständigen Rückverfolgbarkeit vom Stall bis zum Teller und die Pflichtkennzeichnung von genetisch veränderten Nahrungsmitteln mag in der Umsetzung als zu komplex und zu teuer betrachtet werden, insbesondere von den Ländern oder Industriezweigen, welche seit vielen Jahren GVO-Nahrungsmittel hergestellt haben. Dennoch könnte der Ansatz, den europäischen Verbrauchern die freie Wahl für oder gegen GVO zu gewähren, der einzig gangbare Weg sein, bis die Europäer ihr Vertrauen in das Produktions- und Kontrollsystem für Nahrungsmittel zurückgewonnen haben. Eine markt- oder verbraucherorientierte Lösung könnte letztlich den Streit um GVO zwischen den beiden transatlantischen Handelsblöcken beenden. [source] Differences in grey and white matter atrophy in amnestic mild cognitive impairment and mild Alzheimer's diseaseEUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2009M. L. F. Balthazar Background:, Grey matter (GM) atrophy has been demonstrated in amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD), but the role of white matter (WM) atrophy has not been well characterized. Despite these findings, the validity of aMCI concept as prodromal AD has been questioned. Methods:, We performed brain MRI with voxel-based morphometry analysis in 48 subjects, aiming to evaluate the patterns of GM and WM atrophy amongst mild AD, aMCI and age-matched normal controls. Results:, Amnestic mild cognitive impairment GM atrophy was similarly distributed but less intense than that of mild AD group, mainly in thalami and parahippocampal gyri. There were no difference between aMCI and controls concerning WM atrophy. In the mild AD group, we found WM atrophy in periventricular areas, corpus callosum and WM adjacent to associative cortices. Discussion:, We demonstrated that aMCI might be considered a valid concept to detect very early AD pathology, since we found a close proximity in the pattern of atrophy. Also, we showed the involvement of WM in mild AD, but not in aMCI, suggesting a combination of Wallerian degeneration and microvascular ischaemic disease as a plausible additional pathological mechanism for the discrimination between MCI and AD. [source] A metapopulation model for the introgression from genetically modified plants into their wild relativesEVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 2 2009Patrick G. Meirmans Abstract Most models on introgression from genetically modified (GM) plants have focused on small spatial scales, modelling gene flow from a field containing GM plants into a single adjacent population of a wild relative. Here, we present a model to study the effect of introgression from multiple plantations into the whole metapopulation of the wild relative. The most important result of the model is that even very low levels of introgression and selection can lead to a high probability that the transgene goes to fixation in the metapopulation. Furthermore, the overall frequency of the transgene in the metapopulation, after a certain number of generations of introgression, depends on the population dynamics. If there is a high rate of migration or a high rate of population turnover, the overall transgene frequency is much higher than with lower rates. However, under an island model of population structure, this increased frequency has only a very small effect on the probability of fixation of the transgene. Considering these results, studies on the potential ecological risks of introgression from GM plants should look not only at the rate of introgression and selection acting on the transgene, but also at the metapopulation dynamics of the wild relative. [source] Interactions between engineered tomato plants expressing antifungal enzymes and nontarget fungi in the rhizosphere and phyllosphereFEMS MICROBIOLOGY LETTERS, Issue 1 2008Mariangela Girlanda Abstract The introduction of genetically modified (GM) plants in agroecosystems raises concern about possible effects on nontarget species. The impact of a tomato line transformed for constitutive expression of tobacco ,-1,3-glucanase and chitinase on indigenous nonpathogenic fungi was investigated. In greenhouse experiments, no significant differences were found in the colonization by arbuscular mycorrhizal fungi. Diversity indices computed from over 20 500 colonies of culturable rhizosphere and phyllosphere saprotrophic microfungi, assigned to 165 species (plus>80 sterile morphotypes), showed no significant differences between GM and wild-type plants. Differences were found by discriminant analysis in both the rhizosphere and the phyllosphere, but such effects were minor compared with those linked to different plant growth stages. [source] A New Series of Quadrupolar Type Two-Photon Absorption Chromophores Bearing 11, 12-Dibutoxydibenzo[a,c]-phenazine Bridged Amines; Their Applications in Two-Photon Fluorescence Imaging and Two-Photon Photodynamic TherapyADVANCED FUNCTIONAL MATERIALS, Issue 15 2009Marappan Velusamy Abstract A new series of quadrupolar type two-photon absorption (2PA) chromophores 3,9 bearing a core arylamine-[a,c]phenazine-arylamine motif are synthesized in high yields. Palladium-catalyzed Stille coupling and CN coupling reactions are utilized to prepare target chromophores. Detailed characterization and systematic studies of these molecules, including absorption and fluorescence emission, are conducted. These compounds are found to exhibit very large 2PA cross section values, for example, ,7000 GM at 800,nm for 8 in toluene. Two-photon-induced fluorescence imaging is successfully demonstrated in vitro using compound- 8 -encapsulated silica nanoparticles with excellent bio-compatibility. In combination with the capability of both one- and two-photon singlet-oxygen sensitizations, this nanocomposite demonstrates its promising potential in dual functionality toward two-photon fluorescence imaging and two-photon photodynamic therapy. [source] ON THE GEOCHRONOLOGICAL METHOD VERSUS FLOW SIMULATION SOFTWARE APPLICATION FOR LAHAR RISK MAPPING: A CASE STUDY OF POPOCATÉPETL VOLCANO, MEXICOGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 3 2010ESPERANZA MUÑOZ-SALINAS ABSTRACT. Lahars are hazardous events that can cause serious damage to people who live close to volcanic areas; several were registered at different times in the last century, such as at Mt St Helens (USA) in 1980, Nevado del Ruiz (Colombia) in 1985 and Mt Pinatubo (Philippines) in 1990. Risk maps are currently used by decision-makers to help them plan to mitigate the hazard-risk of lahars. Risk maps are acquired based on a series of tenets that take into account the distribution and chronology of past lahar deposits, and basically two approaches have been used: (1) The use of Flow Simulation Software (FSS), which simulates flows along channels in a Digital Elevation Model and (2) The Geochronological Method (GM), in which the mapping is based on the evaluation of lahar magnitude and frequency. This study addresses the production of a lahar risk map using the two approaches (FSS and GM) for a study area located at Popocatépetl volcano , Central Mexico. Santiago Xalitzintla, a town located on the northern flank of Popocatépetl volcano, where volcanic activity in recent centuries has triggered numerous lahars that have endangered local inhabitants, has been used for the case study. Results from FSS did not provide satisfactory findings because they were not consistent with lahar sediment observations made during fieldwork. By contrast, the GM produced results consistent with these observations, and therefore we use them to assess the hazard and produce the risk map for the study area. [source] A numerical comparison of 2D resistivity imaging with 10 electrode arraysGEOPHYSICAL PROSPECTING, Issue 5 2004Torleif Dahlin ABSTRACT Numerical simulations are used to compare the resolution and efficiency of 2D resistivity imaging surveys for 10 electrode arrays. The arrays analysed include pole-pole (PP), pole-dipole (PD), half-Wenner (HW), Wenner-, (WN), Schlumberger (SC), dipole-dipole (DD), Wenner-, (WB), ,-array (GM), multiple or moving gradient array (GD) and midpoint-potential-referred measurement (MPR) arrays. Five synthetic geological models, simulating a buried channel, a narrow conductive dike, a narrow resistive dike, dipping blocks and covered waste ponds, were used to examine the surveying efficiency (anomaly effects, signal-to-noise ratios) and the imaging capabilities of these arrays. The responses to variations in the data density and noise sensitivities of these electrode configurations were also investigated using robust (L1 -norm) inversion and smoothness-constrained least-squares (L2 -norm) inversion for the five synthetic models. The results show the following. (i) GM and WN are less contaminated by noise than the other electrode arrays. (ii) The relative anomaly effects for the different arrays vary with the geological models. However, the relatively high anomaly effects of PP, GM and WB surveys do not always give a high-resolution image. PD, DD and GD can yield better resolution images than GM, PP, WN and WB, although they are more susceptible to noise contamination. SC is also a strong candidate but is expected to give more edge effects. (iii) The imaging quality of these arrays is relatively robust with respect to reductions in the data density of a multi-electrode layout within the tested ranges. (iv) The robust inversion generally gives better imaging results than the L2 -norm inversion, especially with noisy data, except for the dipping block structure presented here. (v) GD and MPR are well suited to multichannel surveying and GD may produce images that are comparable to those obtained with DD and PD. Accordingly, the GD, PD, DD and SC arrays are strongly recommended for 2D resistivity imaging, where the final choice will be determined by the expected geology, the purpose of the survey and logistical considerations. [source] Brain structure and obesityHUMAN BRAIN MAPPING, Issue 3 2010Cyrus A. Raji Abstract Obesity is associated with increased risk for cardiovascular health problems including diabetes, hypertension, and stroke. These cardiovascular afflictions increase risk for cognitive decline and dementia, but it is unknown whether these factors, specifically obesity and Type II diabetes, are associated with specific patterns of brain atrophy. We used tensor-based morphometry (TBM) to examine gray matter (GM) and white matter (WM) volume differences in 94 elderly subjects who remained cognitively normal for at least 5 years after their scan. Bivariate analyses with corrections for multiple comparisons strongly linked body mass index (BMI), fasting plasma insulin (FPI) levels, and Type II Diabetes Mellitus (DM2) with atrophy in frontal, temporal, and subcortical brain regions. A multiple regression model, also correcting for multiple comparisons, revealed that BMI was still negatively correlated with brain atrophy (FDR <5%), while DM2 and FPI were no longer associated with any volume differences. In an Analysis of Covariance (ANCOVA) model controlling for age, gender, and race, obese subjects with a high BMI (BMI > 30) showed atrophy in the frontal lobes, anterior cingulate gyrus, hippocampus, and thalamus compared with individuals with a normal BMI (18.5,25). Overweight subjects (BMI: 25,30) had atrophy in the basal ganglia and corona radiata of the WM. Overall brain volume did not differ between overweight and obese persons. Higher BMI was associated with lower brain volumes in overweight and obese elderly subjects. Obesity is therefore associated with detectable brain volume deficits in cognitively normal elderly subjects. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] Exploring the relationship between white matter and gray matter damage in early primary progressive multiple sclerosis: An in vivo study with TBSS and VBMHUMAN BRAIN MAPPING, Issue 9 2009Benedetta Bodini Abstract We investigated the relationship between the damage occurring in the brain normal-appearing white matter (NAWM) and in the gray matter (GM) in patients with early Primary Progressive multiple sclerosis (PPMS), using Tract-Based Spatial Statistics (TBSS) and an optimized voxel-based morphometry (VBM) approach. Thirty-five patients with early PPMS underwent diffusion tensor and conventional imaging and were clinically assessed. TBSS and VBM were employed to localize regions of lower fractional anisotropy (FA) and lower GM volume in patients compared with controls. Areas of anatomical and quantitative correlation between NAWM and GM damage were detected. Multiple regression analyses were performed to investigate whether NAWM FA or GM volume of regions correlated with clinical scores independently from the other and from age and gender. In patients, we found 11 brain regions that showed an anatomical correspondence between reduced NAWM FA and GM atrophy; of these, four showed a quantitative correlation (i.e., the right sensory motor region with the adjacent corticospinal tract, the left and right thalamus with the corresponding thalamic radiations and the left insula with the adjacent WM). Either the NAWM FA or the GM volume in each of these regions correlated with disability. These results demonstrate a link between the pathological processes occurring in the NAWM and in the GM in PPMS in specific, clinically relevant brain areas. Longitudinal studies will determine whether the GM atrophy precedes or follows the NAWM damage. The methodology that we described may be useful to investigate other neurological disorders affecting both the WM and the GM. Hum Brain Mapp 2009. © 2009 Wiley-Liss, Inc. [source] A multiparametric evaluation of regional brain damage in patients with primary progressive multiple sclerosisHUMAN BRAIN MAPPING, Issue 9 2009Antonia Ceccarelli Abstract The purpose of this study is to define the topographical distribution of gray matter (GM) and white matter (WM) damage in patients with primary progressive multiple sclerosis (PPMS), using a multiparametric MR-based approach. Using a 3 Tesla scanner, dual-echo, 3D fast-field echo (FFE), and diffusion tensor (DT) MRI scans were acquired from 18 PPMS patients and 17 matched healthy volunteers. An optimized voxel-based (VB) analysis was used to investigate the patterns of regional GM density changes and to quantify GM and WM diffusivity alterations of the entire brain. In PPMS patients, GM atrophy was found in the thalami and the right insula, while mean diffusivity (MD) changes involved several cortical-subcortical structures in all cerebral lobes and the cerebellum. An overlap between decreased WM fractional anisotropy (FA) and increased WM MD was found in the corpus callosum, the cingulate gyrus, the left short temporal fibers, the right short frontal fibers, the optic radiations, and the middle cerebellar peduncles. Selective MD increase, not associated with FA decrease, was found in the internal capsules, the corticospinal tracts, the superior longitudinal fasciculi, the fronto-occipital fasciculi, and the right cerebral peduncle. A discrepancy was found between regional WM diffusivity changes and focal lesions because several areas had DT MRI abnormalities but did not harbor T2-visible lesions. Our study allowed to detect tissue damage in brain areas associated with motor and cognitive functions, which are known to be impaired in PPMS patients. Combining regional measures derived from different MR modalities may be a valuable tool to improve our understanding of PPMS pathophysiology. Hum Brain Mapp 2009. © 2009 Wiley-Liss, Inc. [source] A voxel-based morphometry study of frontal gray matter correlates of impulsivity,HUMAN BRAIN MAPPING, Issue 4 2009Koji Matsuo Abstract Impulsivity is a personality trait exhibited by healthy individuals, but excessive impulsivity is associated with some mental disorders. Lesion and functional neuroimaging studies indicate that the ventromedial prefrontal region (VMPFC), including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) and medial prefrontal cortex, and the amygdala may modulate impulsivity and aggression. However, no morphometric study has examined the association between VMPFC and impulsivity. We hypothesized that healthy subjects with high impulsivity would have smaller volumes in these brain regions compared with those with low impulsivity. Sixty-two healthy subjects were studied (age 35.4 ± 12.1 years) using a 1.5-T MRI system. The Barratt impulsiveness scale (BIS) was used to assess impulsivity. Images were processed using an optimized voxel-based morphometry (VBM) protocol. We calculated the correlations between BIS scale scores and the gray matter (GM) and white matter (WM) volumes of VMPFC and amygdala. GM volumes of the left and right OFC were inversely correlated with the BIS total score (P = 0.04 and 0.02, respectively). Left ACC GM volumes had a tendency to be inversely correlated with the BIS total score (P = 0.05). Right OFC GM volumes were inversely correlated with BIS nonplanning impulsivity, and left OFC GM volumes were inversely correlated with motor impulsivity. There were no significant WM volume correlations with impulsivity. The results of this morphometry study indicate that small OFC volume relate to high impulsivity and extend the prior finding that the VMPFC is involved in the circuit modulating impulsivity. Hum Brain Mapp 2009. © 2008 Wiley-Liss, Inc. [source] Assessment of the increase in variability when combining volumetric data from different scannersHUMAN BRAIN MAPPING, Issue 2 2009Santiago Reig Abstract In multicenter MRI studies, pooling of volumetric data requires a prior evaluation of compatibility between the different machines used. We tested the compatibility of five different scanners (2 General Electric Signa, 2 Siemens Symphony, and a Philips Gyroscan) at five different sites by repeating the scans of five volunteers at each of the sites. Using a semiautomatic method based on the Talairach atlas, and SPM algorithms for tissue segmentation (multimodal T1 and T2, or T1-only), we obtained volume measurements of the main brain lobes (frontal, parietal, occipital, temporal) and for each tissue type. Our results suggest that pooling of multisite data adds small error for whole brain measurements, intersite coefficient of variation (CV) ranging from 1.8 to 5.2%, respectively, for GM and CSF. However, in the occipital lobe, intersite CV can be as high as 11.7% for WM and 17.3% for CSF. Compared with the intersite, intrasite CV values were always much lower. Whenever possible, T1 and T2 tissue segmentation methods should be used because they yield more consistent volume measurements between sites than T1-only, especially when some of the scans were obtained with different sequence parameters and pixel size from those of the other sites. Our study shows that highest compatibility among scanners would be obtained using equipments of the same manufacturer and also image acquisition parameters as similar as possible. After validation, data from a specific ROI or scanner showing values markedly different from the other sites might be excluded from the analysis. Hum Brain Mapp, 2009. © 2007 Wiley-Liss, Inc. [source] Structure and biology of complement protein C3, a connecting link between innate and acquired immunityIMMUNOLOGICAL REVIEWS, Issue 1 2001Arvind Sahu Summary: Complement protein C3 is a central molecule in the complement system whose activation is essential for all the important functions performed by this system. After four decades of research it is now well established that C3 functions like a double-edged sword: on the one hand it promotes phagocytosis, supports local inflammatory responses against pathogens, and instructs the adaptive immune response to select the appropriate antigens for a humoral response; on the other hand its unregulated activation leads to host cell damage. In addition, its interactions with the proteins of foreign pathogens may provide a mechanism by which these microorganisms evade complement attack. Therefore, a clear knowledge of the molecule and its interactions at the molecular level not only may allow the rational design of molecular adjuvants but may also lead to the development of complement inhibitors and new therapeutic agents against infectious diseases. A.S. is a Wellcome Trust Overseas Senior Research Fellow in Biomedical Science in India. This research was supported by National Institutes of Health grants AI 30040, GM 56698, HL28220, and AI 48487. [source] Two-Photon Absorption-Related Properties of Functionalized BODIPY Dyes in the Infrared Range up to Telecommunication WavelengthsADVANCED MATERIALS, Issue 10-11 2009Pierre-Antoine Bouit Aza boron-dipyrromethene dyes functionalized by extended donor-,-conjugated moieties present high potentialities for nonlinear applications in the telecommunication spectral range (1300,1500,nm). Their significant two-photon absorption cross-sections (,2,>,600 GM) over this entire spectral range, combined with their high stability and solubility, allow nonlinear transmission experiments. [source] Liquid vorticity computation in non-spherical bubble dynamicsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 2 2005A. A. Aganin Abstract The purpose of this work is to compare efficiency of a number of numerical techniques of computation of liquid vorticity from non-spherical bubble oscillations. The techniques based on the finite-difference method (FDM), the collocation method (one with differentiating (CMd) the integral boundary condition and another without it (CM)) and the Galerkin method (GM) have been considered. The central-difference approximations are used in FDM. Sinus functions are chosen as the basis in GM. Problems of decaying a small distortion of the spherical shape of a bubble and dynamics of a bubble under harmonic liquid pressure variation with various parameters are used for comparison. The FDM technique has been found to be most efficient in all the cases. Copyright © 2004 John Wiley & Sons, Ltd. [source] A grey-box model of next-day building thermal load prediction for energy-efficient controlINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2008Qiang Zhou Abstract Accurate building thermal load prediction is essential to many building energy control strategies. To get reliable prediction of the hourly building load of the next day, air temperature/relative humidity and solar radiation prediction modules are integrated with a grey-box model. The regressive solar radiation module predicts the solar radiation using the forecasted cloud amount, sky condition and extreme temperatures from on-line weather stations, while the forecasted sky condition is used to correct the cloud amount forecast. The temperature/relative humidity prediction module uses a dynamic grey model (GM), which is specialized in the grey system with incomplete information. Both weather prediction modules are integrated into a building thermal load model for the on-line prediction of the building thermal load in the next day. The validation of both weather prediction modules and the on-line building thermal load prediction model are presented. Copyright © 2008 John Wiley & Sons, Ltd. [source] Isolation of DNA from genetically modified oils by fast protein liquid chromatographyINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 7 2010Li Huang Summary In this study, a novel method of fast protein liquid chromatography (FPLC) anion exchange chromatography was developed for isolation of DNA from processed genetically modified (GM) oils. Four kinds of different GM edible oil had been chosen as model sample. Salmon DNA was used as the control sample to determine the pH values and NaCl in mobile phase buffer. Applying pH 8 and NaCl gradient 0.5,2 m were chosen for the DNA isolation. The quality and purity of isolated DNA were tested with agarose gel electrophoresis, scanned with UV absorbance spectra and amplified by polymerase chain reaction (PCR). The result indicated that the quantity of DNA isolated by FPLC was suitable for further PCR analyses. Furthermore, it is more effective and less time-consuming in comparison with cetyltrimethylammonium bromide method and High Pure GMO Sample Preparation Kit method. [source] Consumers' beliefs, attitudes and intentions towards genetically modified foods, based on the 'perceived safety vs. benefits' perspectiveINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2005Ioannis S. Arvanitoyannis Summary It has been repeatedly claimed that the application of genetic engineering in the field of agricultural and food production is both beneficial and advantageous. However, biotechnology is developing in an environment where public concerns about food safety and environmental protection are steadily increasing. The present study aims at gaining an insight into Greek consumers' beliefs, attitudes and intentions towards genetically modified (GM) food products. The objectives of this study are summarized as follows (i) to provide evidence that consumer beliefs are built around the ,safety-benefits' axis, and (ii) to segment the Greek market in terms of consumer beliefs about GM food products and identify a number of clusters with clear-cut behavioural profiles. Although the overall attitude of Greek consumers towards GM food is negative, the research very interestingly concludes that there exists a market segment of substantial size, whose beliefs about GM food appears to be positive. This finding suggests that there is not a ,consensus' regarding the rejection of GM foods in the Greek market as one might have expected thus ,encouraging' the implementation of adequate marketing strategies to target this segment of ,early adopters' in the first place. [source] Performance assessment under field conditions of a rapid immunological test for transgenic soybeansINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2001John Fagan Summary Current market conditions and food regulations make it necessary for international and domestic participants in the agrifood industry to structure supply chains that control the content of genetically modified (GM) material in their products. Tests to detect and/or quantify GM components represent an important tool in maintaining such supply systems. This study assesses the field performance of kits that employ lateral flow immuno-technology to detect soybeans GM to be resistant to the herbicide glyphosate. Operators at 23 grain-handling facilities were paid to conduct analyses on a series of blinded samples containing defined proportions of conventional and transgenic soybeans. The observed rate of false positives was 6.7% in an experiment in which the highest level of GM material was 1% and 22.3% in a second experiment in which the highest level of GM material was 10%. This difference may be attributed to increased risk of cross-contamination with the higher level of transgenic material used in the second study. Samples containing 0.01% GM material were reported as genetically modified 6.70% of the time, while samples containing 0.1, 0.5 and 1% GM material were classified as genetically modified 29.5, 67.7 and 68.2% of the time, respectively. Thus, the frequencies of false negatives were 93.3, 70.5, 33.3 and 31.8% for samples containing 0.01, 0.1, 0.5 and 1.0% GM material. Samples containing 10% GM material were correctly reported as genetically modified in all cases. These results lead to the conclusion that the kit under study is useful in screening for lots of soybeans that contain high levels of GM material, but that, as a field tool, it is not effective in monitoring for GM material at the level of 1.0% or lower. Statistical and immunochemical analyses were carried out in order to assess the relative contributions of various factors to the error observed in these studies. These analyses indicated that limitations in operator performance, not defects in test kit materials, were the primary contributors, while sample size may play a secondary role. As both operator performance and sample size are independent of the specific characteristics of the test kit used in this study, it appears justifiable to generalize conclusions obtained here to other similar test systems. [source] 31Phosphorus magnetic resonance spectroscopy study of tissue specific changes in high energy phosphates before and after sertraline treatment of geriatric depressionINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 8 2009Brent P. Forester Abstract Introduction We investigated tissue specific differences in markers of energy metabolism, including high energy phosphate compounds (beta and total NTP, PCr) and pH, in older adults with depression compared with healthy controls, before and after a 12-week treatment trial of sertraline. Methods Thirteen older adults, age ,55, with Major Depressive Disorder (HAMD17 score of ,18) were recruited along with ten age-matched controls. The depression subjects had a pre- and post-treatment 4T 31P-MRS scan using a three-dimensional chemical shift imaging sequence. The extracted brain images were segmented into white matter (WM), gray matter (GM) and CSF. A linear mixed effects model analyzed the effects of pre-treatment and post-treatment depression on phosphorus metabolite concentration estimates (including calculated pH and Mg++). Results Total tissue beta-NTP (,8%, t(18.66),=,3.50; p,=,0.0024) and total tissue total NTP (,6%, t(17.41),=,2.68; p,=,0.0156) were lower in subjects with geriatric depression compared with healthy controls. Total tissue levels of total-NTP changed significantly with treatment (,2%, t(14.84),=,,2.47; p,=,0.0259). Total NTP was reduced in the WM, but not the GM, in the pre-treatment depression group (t(51.65),=,4.02; p,=,0.0002). Intracellular pH was higher in the GM of subjects with pre-treatment depression (t(1133.84),=,,2.10; p,=,0.0353) and decreased to approximate control levels after treatment (t(648.86),=,,2.53; p,=,0.0115). Discussion These findings demonstrate bioenergetic changes including tissue specific differences in 31P-MRS metabolites in geriatric depression. Decreased white matter total NTP may reflect alterations in white matter function. Copyright © 2009 John Wiley & Sons, Ltd. [source] Is Bt Cotton a Pro-Poor Technology?JOURNAL OF AGRARIAN CHANGE, Issue 4 2010A Review, Critique of the Empirical Record Policy makers, journalists and other commentators have hailed genetically modified (GM) crops as a ,pro-poor' success in the developing world. Their confidence appears to be justified by the encouraging conclusions reached by academic studies on the performance and impacts of GM crops, which seem to provide convincing evidence of substantial benefits for smallholders in developing countries. However, a detailed, critical examination of studies on transgenic, insect-resistant cotton in China, India and South Africa demonstrates that the technology's impacts have been evaluated and represented in selective and misleading ways. The performance and impacts of GM crops have in fact been highly variable, socio-economically differentiated and contingent on a range of agronomic, socio-economic and institutional factors. The shortcomings of the GM crop-impacts literature have done a disservice to public and policy debates about GM crops in international development and impeded the development of sound, evidence-based policy. [source] Determinants of Voter Support for a Five-Year Ban on the Cultivation of Genetically Modified Crops in SwitzerlandJOURNAL OF AGRICULTURAL ECONOMICS, Issue 3 2008Felix Schläpfer D62; D72; Q26 Abstract While much effort has been devoted to estimating market premiums for non-genetically modified (GM) food, the results of such research are largely silent about the preferences for the public good aspects, or externalities, of GM food production. For public goods, the closest substitute of private consumption decisions is voting on referenda. In November 2005, 55.7% of 2 million Swiss voters approved a five-year moratorium (ban) on the commercial cultivation of GM plants in Switzerland. The present study examines how individual voting decisions were determined by: (i) socioeconomic characteristics; (ii) political preference/ideology; and (iii) agreement with a series of arguments in favour and against the use of GM plants in Swiss agriculture. The analysis is based on the data of the regular voter survey undertaken after the national-level voting in Switzerland. The results suggest that current concerns about the use of genetically engineered plants in agriculture may not automatically decrease with higher levels of education/knowledge and generational change. Furthermore, analysis of voter motives suggests that public support for a ban on GM crops may be even larger in other countries, where industrial interests in crop biotechnology are less pronounced. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||